Imagine that the year is 2030 and computer technology has advanced to the point where a sufficiently clever programmer (you, for example) can write software that would project beings on the monitor's screen that can potentially evolve from very simple forms to highly complex structures capable, mirabile dictu, of rational thought.
One evening you download the software that confers upon these creatures this marvelous potential and sit back to watch what they'll do with it. Eventually, after much morphing and mutating, the creatures attain a level of mental ability at which they are capable of reflection, cognition, and language. They begin to communicate among themselves, asking questions about their world and their existence. To them their world (we'll call it "screen world") is a three dimensional space since, although they are confined to a flat screen, they think themselves, like characters on a movie screen, to move in all directions. You're very pleased with your creation. You even find yourself growing fond and attached to these creatures, which you dub "screenies."
As the night lengthens, you watch in rapt fascination as one of your screenies begins to think deeply about what exactly it (let's assume it's a "he") is. At first he explains himself in terms of shifting phosphor dots, but this, he realizes, is only a superficial level of explanation, and the screenie isn't satisfied with it. There must be a deeper understanding, a deeper level of reality, a reality that lies beyond the abilities you've programmed into the screenies to apprehend.
He and his fellows do some mathematical calculations and come to a breathtaking conclusion. The "ultimate" explanation for the population of creatures in screen world is a level of reality that they can never observe or visit, but which must exist. The equations demand it. They realize that there must be a whole set of complicated phenomena working to produce emanations from a multi-dimensional tube (Cathode Ray Tube) that somehow generates the relatively "flat" world they inhabit.
They do more calculations and come to an even more astonishing discovery. The CRT must be controlled by an even deeper level of phenomena: electrons, circuits, and microchips and who knows what all else. Finally, awed by their findings, they realize that this whole theoretical edifice they've constructed must be run by an information source, a set of algorithms and codes, that exists somewhere but is inaccessible to them.
Your creatures are very excited. They have plumbed the basic laws, parameters, forces and material constituents of their world. They don't know where these ultimate elements come from or how they came to be organized in the fashion they are, and indeed they're convinced that they can never know this for certain. They have taken their investigation as deep as it is possible for them to go, they believe. The rest they simply accept as a brute fact. A given.
Then these marvelous beings, which have really sprung from your creative genius, draw a disappointing philosophical conclusion. Having explained their existence in terms of the ultimate physical constituents and laws they've deduced from the phenomena of their experience, they conclude that that is all there is to be explained. Those circuits, microchips, electrical energy and even the software are all that's involved in generating them and their world. It's an amazing thing, they agree, it's highly improbable they acknowledge, but there you have it. There's no need to explain it any further, nor any way to explain it even if there were a need.
Screen world is, in their considered opinion, totally explicable in terms of the machinery in front of which you sit shaking your incredulous head. You're delighted that your creatures were able to reason their way so far toward the truth but dismayed that they lacked the wit to see that anything as fantastically complex as the laws and processes that generate their world cries out for even deeper explanation. Why, you wonder, don't the screenies realize that something as amazing as they and their world don't just happen through blind luck? Why don't they recognize that screen world demands an intelligent cause as its truly ultimate explanation?
You decide to tweak the program. You write the code for another being, one that is, perhaps, somewhat of a cyber-replica of yourself. You will in a sense visit screen world yourself through this "agent." He contains much of your knowledge about the reality beyond screen world, and when you download him into the computer up he pops on the screen. You've programmed this agent to tell the rest of the screenies that their world, the world of the monitor and even the deeper world of the computer, is an infinitesimal fraction of the really real.
Your agent proceeds to explain to them as best he can that they, contrary to their belief, actually inhabit only two dimensions and that all around them lies a third dimension that they could never perceive or comprehend but which nevertheless exists, and that even now you, their creator, are observing them from outside the screen in another world that they cannot begin to conceptualize, much less observe, from their "prison" within the screen.
Your agent reveals to them, moreover, that you inhabit a reality infinitely richer than screen world, an idea they unfortunately find wholly preposterous. He tells them that as wonderful and impressive as their discoveries about their world are they've really just scratched the surface of understanding the really real and that, indeed, they aren't actually "real" themselves at all. They're simply epiphenomenal electronic manifestations of ideas in your mind, a congeries of shifting dots of color on a flat screen. They're in fact nothing more than virtual beings.
They scoff at all this. They grow angry. They tell your agent to get lost, his message is confusing and misleading to the young and impeding progress toward the goal of making screen world a better place. They wish to hear no more of the his insane, superstitious babblings. They are the "brights" in screen world and they will stick to science and leave his untestable metaphysical speculations to the priests and shamans among them.
When the agent persists in trying to persuade them that mere mechanical processes could never by themselves produce such complex creatures as screenies, that the algorithms and coordinated flows of energy and pattern in their world, as well as the material organization of the computer, must have been intelligently engineered, they sneer and refuse to allow him to speak such nonsense any further.
They reason among themselves that their existence may be improbable, but what of it? Had their world not been the way it is they would not be there to observe it, so it's not so extraordinary after all. Others say that there are probably a near infinite number of worlds like theirs, and that among so many it's not so astonishing that there'd be one possessing the properties that screen world has and boasting the creatures called screenies.
You're surprised, and a little hurt, that they react this way. You can't believe that having come so far they would refuse to entertain the idea that there must be more to the origin of the information that infuses their world than just blind matter, brute force and random chance. But they're obstinate. They have all the explanation for their existence they care to have.
To be dependent upon unthinking processes is one thing - they're still superior, after all, to the processes and forces upon which they are contingent because they can think and those processes can't. But to be dependent upon a being who is so thoroughly superior to them in every way is, well, degrading. So that they might appreciate you, you entertain briefly the idea of adjusting their software in such fashion as to make the conclusion that an intelligent programmer has created them ineluctable. You decide against it, however, when you realize that compelled appreciation is no appreciation at all.
And so, with a sad sigh of disappointment and resignation, you shut down the computer and go to bed.